Tread portion of an automobile tire



FIG. 1 is a perspective view of a tread portion of an automobile tire;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a fragmentary enlarged view showing the details of the tread portion; and,

FIG. 5 is an end view taken along line 5-5 in FIG. 4.

Broken lines are used to show portions of the tire other than the tread portion, and thus form no part of the claimed design. 

The ornamental design for a tread portion of an automobile tire, as shown and described. 